The present disclosure relates to mattresses, support pads, cushions, and the like. More particularly, the present disclosure relates to mattresses, support pads, etc. having a foam piece situated within a cover to which suction is applied to reduce the volume of the foam piece.
Mattresses, support pads, cushions, and the like that have one or more foam pieces surrounded by a covering or casing to which suction or vacuum is applied to reduce the volume of the one or more foam pieces are known. See, for example, U.S. Pat. Nos. 6,092,249; 5,159,726; and 3,730,588.
It is known that high interface pressures between a person and a pad, mattress, etc. supporting the person can lead to unwanted complications such as decubitus ulcers or pressure sores. Thus, it is desirable to minimize interface pressures between a person and the underlying support structure. It is known that mattresses and pads made of softer foam having low indentation load deflection (ILD) values, in general, produce lower interface pressures than mattresses and pads made of harder foam having high ILD values. However, low ILD foam is easily compressible and therefore, a rather large thickness of low ILD foam is needed to prevent “bottoming” of a body supported by the low ILD foam. Bottoming occurs when a foam element, or any type of support element, no longer supports the body, but rather, the body is being supported by whatever structure is beneath the element.